Electric heater.



E. N. BROWN.

ELECTRIC HEATER.

APPLICATION FILED DEC.26. 1911.

1,255,814. Patented Feb. 5,1913.

j ected outwardly for the purpose of controlling UNITED STATES PATENT OFFICE.

EDMUND N. BROWN, 01 SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO MAJESTIC ELEC- TRIO DEVELOPMENT CO., A CORPORATION OF CALIFORNIA.

ELECTRIC HEATER.

Specification 01' Letters Patent.

Patented Feb. 5, 1918.

Application filed December 26, 1917. Serial No. 208,965.

To all whom it may concern:

'Be it known that I, EDMUND a citizen of the United States, residing at San Francisco, in the county of SanFranciscoand State of California, have invented certain new and useful Improvements in Electric Heaters, of which the following is a s ecification. I

his invention relates to electric heaters or radiators in which the heat waves generated by a resistance coil are directed by means of a polished metal reflector.

The objects of my invention are to greatly increase the efliciency of electric heaters of this type and to provide a heater in which the heat waves which strike the polished surface are reflected in parallel lines, so that substantially all of the heat Waves are proas a column or shaft of heated currents. The heating effect of an electric radiator embodying my invention will be felt for a reater distance by reason of this manner of projection and the shaft of heated currents may be utilized in positively controlling the air currents of a room or space and may, therefore, be employed the ventilation of a room. I believe this to be entirely N. BROWN,

new in the art of electric heating. It has,

of course, lon been the custom to provide a reflecting surface back of the electric heating unit and these surfaces have been made of various configurations. In so far as I am aware, however, no construction prior to my invention has provided an electric radiator wherein the heat rays were projected in substantially parallel lines so that practically the entire mass of heat rays are projected as a column or shaft of heat. I attain this object by concentrating the heat generating coil as near as may be at or about the foca point of a parabolic reflector and to this end wind the heatin coil about a short axis passin through t e focal point. transverse to the longitudinal axis of the parabolic reflector. I

In the accompanying drawings, Figure 1 is a front erspective view of an electric radiator, em odying' my invention; Fig. 2 is ing member 3 which is of such configuratlon as to leave an intervening air chamber 4 and may also be provided with an annular marginal rim or flange 5 to which guard wires 7 may be fastened. The backing member, annular flange and guard wires remain comparatively cool, thereby avoiding the possibility of coming in contact with a highly heated metal portion. The reflector may be provided with any suitable standard or base 10 which may secured in a suitable manner to the backing member 3.

The heating unit consists preferably of a coil of resistance wire 12 wound upon an insulating spool of porcelain or other suitable material 14, the latter having in through the focal point of the parabolic reflector and being suitably supported as by means of standards 15 adjacent either end. I have shown the heating unit secured to the standards by attaching the ends of the coil 12 thereto and this connection may be reinforced by means of an additional wire twist; ed with the end connections and, if desired, also encircling the'.ends of the spool 14. The standards may be insulated from the reflector by having the bolt securing it thereto pass through insulating washers, the bolts also forming the electrical connections and being connected to the terminals of the cord conductor 17, the latter, of course, being provided on its outer end with a plug connecmanner. It is obvious that instead of utilizing the terminal of the resistance coil to support the heating unit, additional supports may be provided and secured to the reflector.

It is well known that the inner surface of a shell generated by the revolution of a parabola has such a configuration that if lines were drawn in an direction from the focal point to said sur ace,the corresponding lines of reflection therefrom would be parallel with the principal axis of said surface, and paraboloidal surfaces have been used in various arts, such as parabolic mirrors used in reflecting telescopes and the reflectors used in search lights. Prior to my discovery of the peculiar advantages and the greatly increased efiiciency which result from the concentration of the generating unit about the focal point of a parabolic reflector in electric heaters, this principle has never been used in the art of electric heating. While, of course, the heat waves generated by the heating units in prior electric heaters are reflected from the curved reflecting surfaces, these heat waves emerge from the reflector at various angles so that the greater proportion of the heat will be felt only a short distance from the radiator and for certain purposes of general heating this is suflicient; whereas I have found that the penetration of the heat or the distance which it may be projected from the radiator is very largely increased by the arrangement disclosed in my present application. By reason of this fact, I am enabled to locate the heater in a more convenient place or position in a room or space While still projecting the heat waves to the desired point. Thus if it were desired to have the heat felt at or near a certain chair positioned at a desk or at a point under the desk, my heater may be placed at a convenient distance away from the desired heat center, instead of being placed directly at the place to be heated.

I have described in detail the particular construction illustrated in the accompanying drawing for the purpose of disclosing an embodiment of my invention, but it will be evident to engineers that various changes and modifications may be. made within the scope of my claims and without in any manner departing from the spirit of my invention. Thus, the heating unit may be made of a different shape or configuration so long as the heater resistance wire is substantially concentrated about the, focal point of the reflecting surface; and it is also evident that it would not be a departure from my invention to lengthen the heating coil beyond the effective axial len th 50 that a certain portion thereof woul extend beyond the range of parallel reflection while the major portion would be substantially within this effective range about the focal point.

I claim:

1. An electric heater comprising a parabolic reflecting surface and an electric heating unit passing through the focus-thereof transversely to the axis, whereby the heat i will be reflected from said surface in substantially parallel lines.

2. An electric heater, comprising a parabolic reflecting surface, and an electric heating unit comprising a resistance wire carried by an insulating support of small dimensions substantially centered aboutthe focal point of the reflector, whereby the heat waves will be reflected from said surface in substantially parallel lines.

3. An electric heater, comprising a substantially parabolic reflector having a polished reflecting surface, an electric heating device mounted at substantially the focus of said parabolic reflecting surface and comprising a resistance wire coiled about a short axis passing substantially through the focal point of the reflector and transversely to the axis thereof, whereby the heat will be generated near the focus of the reflector and be reflected from the surface thereof in substantially parallel lines.

In testimony whereof I aflix my signature.

EDMUND N. BROWN. 

